Jim McIntyre’s men lost a goal after 27 seconds but Efe Ambrose lost his bearings 12 minutes later and from then on County showed up Ronny Deila’s team.

Yes, there were similarities to last season’s Scottish Cup semi-final defeat, but only in terms of Celtic going a goal up against Highland opposition, only to concede a penalty and red card before losing.

That defeat against Inverness Caley Thistle left Ronny Deila’s men feeling robbed. But yesterday they were merely rotten. This was Ross County’s day and they now stand just 10 minutes from emulating their neighbours by taking silverware up north.

Celtic were outplayed by a team with a quartet of players who were deemed good enough top make it at Parkhead and one them, goalkeeper Scott Fox, even saved a Leigh Griffiths penalty that could have thrown Celtic a lifeline at 3-1 down. The others, Marcus Fraser, Michael Gardyne and Jackson Irvine more than played their part in victory that would have been celebrated long into the night.

But what now for Deila? Another Treble dream is up in smoke and there can be few complaints. A team with tiny resources outplayed and outfought them from the minute Martin Woods’ penalty - after Ambrose had been sent off for clipping Alex Schalk - hit the back of Craig Gordon’s net.

Celtic were massive favourites but knew from bitter experience that nothing could be taken for granted and they started like a team hellbent on not leaving anything to chance - or to the vagries of a refereeing decision. And boy, was there a big one to come in this match.

In just 27 seconds they ripped County to shreds and were a goal to the good before most of the players on the pitch had even touched the ball.

The goal was sparked by Callum McGregor’s incisive jab to Griffiths, which found the striker sprinting away from his markers and careering towards Scott Fox.

This is where Griffiths displayed his growing maturity. Everyone in the ground, including Fox, expected him to take on the shot, but Griffiths glanced to his right, saw Mackay-Steven in acres of space, and slid the winger in for a tap-in.

Celtic's Efe Ambrose is sent off (Image: SNS)

It was dream start for Deila and a nightmare for McIntyre, which threatened to get worse in the fourth minute when Efe Ambrose rose highest to meet a McGregor corner. Had the Nigerian’s header not been hoofed off the line by Richard Foster, this tie would have been over by five past three.

But those roles were reversed in the 12th minute when Irvine’s flick into the box caught out Ambrose and allowed Schalk in behind him.

The Dutchman cut across the defender 10 yards from goal and was clipped by Ambrose. There wasn’t much contact, but there was enough and even as Schalk hit the deck, Craig Thomson was reaching for his red card with one hand and pointing to the spot with the other.

Ambrose looked perplexed but had he cleared his lines in the first place, it wouldn’t have happened. Deila immediately threw on Erik Sviatchenko for an unexpected debut, sacrificing McGregor and forcing Martin Woods to wait an eternity on the penalty spot.

Didn’t matter. The former Scotland Under 21 midfielder calming sent Gordon the wrong way and County were level and a man to the good.

Ross County's Martin Woods makes it 1-1

Deila switched his team to a straightforward 4-4-1 and they continued to have more of the ball. McIntyre brought on Jonathan Franks for Stewart Murdoch, who had been booked, in the 27th minute, in a move designed to remain a player up.

As the half progress, it was the blue-shirted team which began to gain control, edging into Celtic territory and staying there. Gordon had to beat away a fierce drive from Woods which almost surprised him and at that stageMcIntyre’s men sniffed a real opportunity.

They had Fox to thank for keeping them level in rhe 40th minute, though. The keeper made a flying one-handed save to keep out a Mikael Lustig header from Stefan Johansen’s corner and dived bravely to block Nir Bitton’s follow-up strike. Fox was then clattered, accidently, by Sviatchenko as he scrambled around on the deck but he kept the ball in his grasp.

It took County just three minutes into the second half to hit the front and this had nothing to do with numerical advantage - just rank bad Celtic defending.

Woods’ corner hung in the air forever, allowing Andrew Davies to peel away unchallenged from Johansen. The captain headed the ball back across goal for Quinn, standing unmarked on the six yard line to nod past Gordon.

Ross County's Paul Quinn makes it 2-1

This was now a major test for Deila and his team. A goal and a man down and as the hour mark passed, they hadn’t laid a second half glove on their opponents.

And in the 62nd minute they left their chin out hanging out and Schalk knocked them out.

Woods, who had a field day, charged forward from the middle of the park to feed the Dutchman, who stepped away from Dedryck Boyata to slam a glorious left footer high past Gordon at his near post.

Deila wasn’t on the touchline when his team conceded and just sat where he was for the next few minutes until he sent on Scott Brown for what would have been the rescue mission to end them all. Even then, the decision to remove Bitton for Brown was greeted with howls of derision.

Brown cattle-prodded his team into action and they began to fight back into the game but there remained a distinct lack of quality about their work. They had a big penalty claim denied in the 71st minute when Michael Gardyne clashed with Lustig in the box but Thomson waved play on.

Alex Schalk of Ross Country celebrates with captain Andrew Davies

And even when the whistler gave Celtic a spot kick in the 77th minute, they still couldn’t take advantage,

Sub Brian Graham headed a Johansen corner off his own arm and to the striker’s horror, Thomson pointed to the spot. He need not have worried - Griffiths slammed his effort straight down the middle and Fox blocked it to spark more celebrations in the County support.

Almost immediately, their team raced to the other end and it took a magnificent stop from Gordon from Irvine to prevent his team going 4-1 behind.

Griffiths was denied by Fox again three minutes from time and perhaps if that shot had gone in there would have been a frantic finish.

It wasn’t to be. Celtic were out and without much of a fight - the better team won on the day and the fingers of blame cannot be pointed at anyone but themselves.